<?php

// +----------------------------------------------------------------------

// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]

// +----------------------------------------------------------------------

// | Copyright (c) 2006-2012 http://thinkphp.cn All rights reserved.

// +----------------------------------------------------------------------

// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )

// +----------------------------------------------------------------------

// | Author: liu21st <liu21st@gmail.com>

// +----------------------------------------------------------------------

namespace Think\Cache\Driver;

use Think\Cache;



defined('THINK_PATH') or exit();

/**

 * Memcache缓存驱动

 * @category   Extend

 * @package  Extend

 * @subpackage  Driver.Cache

 * @author    liu21st <liu21st@gmail.com>

 */

class Memcachesae extends Cache {



    /**

     * 架构函数

     * @param array $options 缓存参数

     * @access public

     */

    function __construct($options=array()) {

        if(empty($options)) {

            $options = array (

                'host'        =>  C('MEMCACHE_HOST') ? C('MEMCACHE_HOST') : '127.0.0.1',

                'port'        =>  C('MEMCACHE_PORT') ? C('MEMCACHE_PORT') : 11211,

                'timeout'     =>  C('DATA_CACHE_TIMEOUT') ? C('DATA_CACHE_TIMEOUT') : false,

                'persistent'  =>  false,

            );

        }

        $this->options      =   $options;

        $this->options['expire'] =  isset($options['expire'])?  $options['expire']  :   C('DATA_CACHE_TIME');

        $this->options['prefix'] =  isset($options['prefix'])?  $options['prefix']  :   C('DATA_CACHE_PREFIX');

        $this->options['length'] =  isset($options['length'])?  $options['length']  :   0;

      //  $func               =   isset($options['persistent']) ? 'pconnect' : 'connect';

        $this->handler      =  memcache_init();//[sae] 下实例化

        //[sae] 下不用链接

        $this->connected=true;

        // $this->connected    =   $options['timeout'] === false ?

        //     $this->handler->$func($options['host'], $options['port']) :

        //     $this->handler->$func($options['host'], $options['port'], $options['timeout']);

    }



    /**

     * 是否连接

     * @access private

     * @return boolean

     */

    private function isConnected() {

        return $this->connected;

    }



    /**

     * 读取缓存

     * @access public

     * @param string $name 缓存变量名

     * @return mixed

     */

    public function get($name) {

        N('cache_read',1);

        return $this->handler->get($_SERVER['HTTP_APPVERSION'].'/'.$this->options['prefix'].$name);

    }



    /**

     * 写入缓存

     * @access public

     * @param string $name 缓存变量名

     * @param mixed $value  存储数据

     * @param integer $expire  有效时间（秒）

     * @return boolean

     */

    public function set($name, $value, $expire = null) {

        N('cache_write',1);

        if(is_null($expire)) {

            $expire  =  $this->options['expire'];

        }

        $name   =   $this->options['prefix'].$name;

        if($this->handler->set($_SERVER['HTTP_APPVERSION'].'/'.$name, $value, 0, $expire)) {

            if($this->options['length']>0) {

                // 记录缓存队列

                $this->queue($name);

            }

            return true;

        }

        return false;

    }



    /**

     * 删除缓存

     * @access public

     * @param string $name 缓存变量名

     * @return boolean

     */

    public function rm($name, $ttl = false) {

        $name   =   $_SERVER['HTTP_APPVERSION'].'/'.$this->options['prefix'].$name;

        return $ttl === false ?

            $this->handler->delete($name) :

            $this->handler->delete($name, $ttl);

    }



    /**

     * 清除缓存

     * @access public

     * @return boolean

     */

    public function clear() {

        return $this->handler->flush();

    }



    /**

     * 队列缓存

     * @access protected

     * @param string $key 队列名

     * @return mixed

     */

    //[sae] 下重写queque队列缓存方法

    protected function queue($key) {

        $queue_name=isset($this->options['queue_name'])?$this->options['queue_name']:'think_queue';

        $value  =  F($queue_name);

        if(!$value) {

            $value   =  array();

        }

        // 进列

        if(false===array_search($key, $value)) array_push($value,$key);

        if(count($value) > $this->options['length']) {

            // 出列

            $key =  array_shift($value);

            // 删除缓存

            $this->rm($key);

            if (APP_DEBUG) {

                    //调试模式下记录出队次数

                        $counter = Think::instance('SaeCounter');

                        if ($counter->exists($queue_name.'_out_times'))

                            $counter->incr($queue_name.'_out_times');

                        else

                            $counter->create($queue_name.'_out_times', 1);

           }

        }

        return F($queue_name,$value);

    }



}

